The present invention relates generally to bicycle shifters, and more particularly, is directed to a shift lever arrangement for a bicycle using a single lever movable along two orthogonal axes for shifting in different directions.
Conventionally, shifters for bicycles have been mounted on the handlebar, separate and apart from the brake levers. Generally, there is single lever that is rotatable in one direction for upshifting and rotatable in the opposite direction for downshifting.
It is, however, to provide different tactile sensations when shifting in the different directions. In this regard, U.S. Pat. No. 5,921,138 to Kojima et al discloses a first lever that is linearly movable for shifting in a first direction and a separate second lever that is pivotally movable in a second different direction for shifting in an opposite direction. However, this requires two different levers, even though the tactile sensations are different.
U.S. Pat. No. 7,527,137 issued May 5, 2009 to the same inventor herein, discloses a single lever that effects a braking operation and a gear shifting operation. A rod moves inside the shift lever in the linear direction, but also requires pivoting movement thereafter of the shift lever, in order to effect a shifting operation. Specifically, to provide a reverse shifting operation, a push button is depressed. As a result, a caroming surface in the shift lever engages a roller wheel to push a plunger rod in the shift lever up against the force of a linear coil spring associated therewith. The flat upper surface of the plunger rod engages the free engagement end of a cable carrier pawl 100. Then, with the push button still depressed, the shift/brake lever is again pivoted about its pivot pin to effect the reverse shifting operation. Thus, this patent requires linear movement of a rod inside of the pivot lever, and also, pivoting movement of the lever thereafter. Further, this arrangement is greatly complicated because it also requires that the single lever be used for a braking operation as well.
The inventor herein has also invented an arrangement which is the subject matter of copending U.S. patent application Ser. No. 11/434,324, filed May 15, 2006 in which a single lever is used for a braking operation as well as gear shifting in both directions. In this invention, the single lever is pivoted in a first direction for performing a braking operation, pivoted in a second direction for performing a first gear shifting operation, and movable only in a linear direction in the longitudinal direction of the shift lever for performing a second opposite gear shifting operation without pivoting of the single lever.
This latter arrangement, however, becomes relatively complicated because of the inclusion of the braking arrangement with the single lever.
It is therefore desirable to provide a single lever that is used for shifting in opposite directions with different tactile sensations, but which is not used for braking.